XVIII Международная студенческая научная конференция Студенческий научный форум - 2026

Introduction. Sickle Cell Anaemia (SCA) is an inherited RBC disorders caused by mutation in the HBB gene which is found on chromosome number 11, which affects haemoglobin responsible to carry oxygen.

Causes. SCA is caused by the changes or variation in both the copies of the HBB gene, it provides the instructions for making a protein called Beta-globin it is a component of haemoglobin inside the RBCs which carries the oxygen from lungs to all parts of the body. The normal RBCs are round and flexible so they move easily through blood vessels and have life span of 120 days but in case of SCA, RBCs are sickle or crescent shaped, these cells become rigid, sticky and have life span of 16 days, which cause the shortage of RBCs, after death they get stuck on the blood vessels and cause the blockage in blood flow which results in a range of complications like severe pain, infection, shock, organ damage and anaemia [1].

The variation in the HBB gene that results in the production of an abnormal version of beta-globin called haemoglobin S (HbS) that causes the change in a single component of beta-globin protein. Specifically, at the 6^th position of Beta-Globin, Glutamic acid is replaced by the amino acid Valine (Glu6Val). This abnormal subunit of haemoglobin S that sticks together and forms a long rigid molecule that bends RBCs into sickled shape. HbSD, HbSS, HbS beta thalassemia gene, HbSC, HbSO, HbSE are the other variants of mutated HBB. HbSS SCA occurs when individual inherits two genes that code for haemoglobin ‘S’. HbSC SCA occurs when individual inherits one haemoglobin ‘S’ and one ‘C’ gene. HbS beta thalassemia occurs when an individual inherits one ‘S’ gene and Beta thalassaemia gene. HbSE is produced when glutamic acid is replaced by lysine amino acid at position of 26 of beta globin (Glu26Lys OR E26K).
People with one allele of an mutated HBB gene are said to have carrier of SCA (one HbA and one HbS) these people have both normal RBCs and sickled RBCs, these people do not have any symptoms of SCA, although in rare cases, might develop severe complications like pain crises, etc. the sickle cell trait protects against uncomplicated malaria like in Africa, parts of India, the Middle East and Central America [2].

Symptoms:
1. Anaemia: SCs have shorter lifespan which cause shortage in RBCs.

2. Painful Sickle Cell crises: SCs blocks the blood flow which cause intense pain in bones, chest, abdomen or joints.

3. Acute Chest Syndrome: due to the blockage in lungs cause acute chest pain characterized by fever, and respiratory distress.

4. Jaundice: the rapid breakdown of CSs causes yellowing of body and whiting of eyes.
5. Priapism: a painful, prolonged erection due to blockage blood flow, which leads to impotence if untreated.

6. Splenic Sequestration: spleen gets filled with SCs which leads to anaemia and spleen damage or removal.

7. Increase Stock Risk: these cells can block blood vessels in the brain. Increases the risk of stroke.

8. Swelling: particularly in hands and feet of the baby known as dactylitis
9. Vision Problem: damage in retina because of blockage in blood vessels. Delay growth in children in adolescents because of anaemia or other problems [3].

Treatment. There is no universal cure for SCA. The treatment of SCA is focused on preventing and treating pain episodes and other complication. Health maintenance for patient with sickle cell anaemia starts early diagnosis in newborn period. In 2017, 2019, 2023 FDA approved various drugs for treatment of SCA of folic acid.
FDA Approved Medication

-Hydroxyurea: standard care to reduce pain crises acute chest syndrome and the need for blood transfusion

- L-glutamine (Endari): an oval powder approved for patients age 5 and older to prevent pain crises.

-Crizanlizumab (Adakveo): an intravenous infusion administered monthly for patients age 16 and older to prevent pain crises.

Curative and Advanced Therapies

- Gene Therapy: it involve editing patient’s own stem, cell considered potentially curative but requires long term monitoring.

- Stem Cell Transplant: a known cure that replace sickle stem cells with healthy once from a donor it is risky requires well matched donor.

Supportive Medical Care

- Blood Transfusion: help reduce the risk of stroke and pain by increasing healthy RBCs.
- Iron Chelation: chronic transfusion can cause dangerous iron building in organs specifically are used to remove iron.

Holistic Management

- Preventative Care: staying up to date on vaccine and attending regular screening with a haematologist.

- Reproductive Planning: genetic counselling helps of passing on the disease and explores testing option.

- Mental Health: prioritizing sleep, exercise and therapy to manage the stress of living with a chronic illness [4].

References:

1. Sickle Cell Disease: Causes, Symptoms, and Treatment / William Coetzee, Reiner Khumalo, Brendan Le Roux, Ebrahim Van Wyk // Fusion of Multidisciplinary Research, An International Journal (FMR). – 2022. – Vol. 3, Iss. 1. – С. 275-286. – Text electronic. – URL: https://www.researchgate.net/publication/392390552_Sickle_Cell_Disease_Causes_Symptoms_and_Treatment (data accessed: 25.12.2025).

2. Sickle Cell Disease // Rare Diseases. – Text electronic. – URL: https://rarediseases.org/rare-diseases/sickle-cell-disease/ (data accessed: 29.12.2025).

3. Sickle-cell disease // World Health Organization. – Text electronic. – URL: https://www.who.int/news-room/fact-sheets/detail/sickle-cell-disease (data accessed: 26.12.2025).

4. About Sickle Cell Disease // Sickle Cell Disease Association of America. – Text electronic. – URL:  https://sicklecelldisease.org/about-sickle-cell-disease/ (data accessed: 26.12.2025).

*The review article has been written under the guidance of Associate Professor of biology department of Orenburg State Medical University, Cand. Sc. (Biology), G.F. Kolchugina

*Данная обзорная статья написана под руководством доцента кафедры биологии Оренбургского государственного медицинского университета, кандидата биологических наук Г.Ф. Кольчугиной.